Underwater launched surface mine



April 9, 1963 c. H. HOLM 3,08

UNDERWATER LAUNCHED SURFACE MINE Filed Dec.

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April 9, 1963 c. H. HOLM 3,084,627

UNDERWATER LAUNCHED SURFACE MINE Filed Dec. 15. 1960 2 Sheets-Sheet 2 Fig. 5

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llnitecl grates UNDERWATER LAUNCHED SURFACE MENE Carl B. Helm, Dcbhs Ferry, N.Y., assignor to the United States of America as represented by the Secretary of the Navy Tiled Dec. 15, 196i), Ser. No. 76,077 3 Claim. (Cl. 102-11?) (Granted under Title 35, US. Code (E52), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to the defense of a submarine against an attacking surface vessel and more particularly to a water surface mine adapted to be launched from a submerged vessel.

An object of the invention is to provide a weapon against surface vessels which can be carried in a flooded area of a submarine and launched therefrom While the submarine is submerged.

Another object of the invention is the provision of a compactly packaged water surface mine which when launched from a submerged vessel will rise to and assume a linear configuration on the water surface.

A further object of the invention is to provide an elongated water surface mine which when engaged and dragged through the water by a surface vessel will explode.

Other objects as well as the attendant advantages of the invention will be better understood from the following description of the preferred embodiment of the invention when read in connection with the accompanying drawing in which:

FIG. 1 is a diagrammatic view showing successive stages of a launched mine;

P16. 2 is a view partly in section of a packaged mine prior to launching;

FIG. 3 is a fragmentary view in section showing an arrangement for exploding a mine;

FlG. 4 shows a pressure relief and sterilizing valve; and

PEG. 5 shows a lanyard severing pincer.

in accordance with the invention, an elongated line charge is encased by a flexible fluid tight tubular member pinched together at intervals for articulation and the intervening segments filled with high explosive resembling sausage links. To insure that the plurality of explosive segments constitute a single charge when the array assumes a linear configuration, a short length of detonating fuse is positioned in each articulation and in contact with adjacent segments of high explosive. The line charge is compactly packaged in zigzag-fashion and placed within a suitable container for stowage in a flooded area of a submarine, preferably in a cradle carried by the superstructure and preferably aft of the sail. The container is provided with means operated from within the submarine for rendering itself buoyant, the arrangement being that as the container becomes buoyant it launches itself by rising from its cradle and thereafter ejects the line charge which is provided with means operable upon ejection to inflate the tubular casing of the line charge to cause it to rise to the surface and to assume a linear configuration. Also in accordance with the invention, devices for exploding the line charge are provided with operating means responsive to forced movement through the water as by raster? Patented Apr. 9, 1963 being dragged by a surface vessel encountering the line charge.

The preferred embodiment of the invention shown in FIG. 2 comprises a cylindrical container having its forward end closed by a hemispherical wall portion 11 and having its rear end closed by a removable bulkhead 12 which is rendered fluid tight as by an O-ring seal 13. Slidably received within the cylindrical portion of the container 10 is a surface mine comprising a packaged line charge having a flexible fluid tight tubular casing 14 of circular or rectangular cross-section pinched together at intervals 15 for articulation with the intervening segments being filled with high explosive such as TNT and folded together in zigzag-fashion to form a compact bundle which may be held together by one or more encircling bands 16 having their ends secured by a pelican hook 17 retained in securing position by the walls of the container 10. The voids around the packaged line charge 26} as Well as the chamber formed by the hemispherical wall end 11 are flooded with fresh water, preferably distilled, through a filler opening sealed by a threaded plug 18. The reason the container 10 is flooded with water is to enable it to withstand being submerged to great depths and also to prevent the access of sea water. The chamber enclosed by the end wall 11 is provided with an inflatable bladder 19, such as a weather balloon, having its mouth connectable in a known manner to a source of gas 21 under pressure upon the rotation of a bell crank 22. This bell crank 22 may be rotated through a lanyard 23 and a lanyard grip 24 having a pull rod 25 extending through the deck plate 26 of a submarine 27 (FIG. 1). The lanyard 23 may also be provided with a pincer 28 (see FIG. 5) for severing the lanyard 23 after the gas filled bottle 21 has been punctured so that the buoyancy resulting from the inflation of the bladder I? can lift the container lll free from the deck 26, a simple spring loaded poppet valve 29 being provided in the wall 11 to allow displacement of the fresh water from the container 10. The flexible tubing 14 is also provided with one or more associated sources 31 of gas under pressure adapted to inflate the tubing 14 upon rotation of a bell crank 32 which is connected to a lanyard 33 secured at its other end to an eye 34 on the inner wall of the container Ill, the arrangement being that as the packaged tubing 14 is ejected from the container 10 the lanyard 33 becomes taut and the bell crank 32 is rotated to initiate inflation of the tubing 14. The bell crank 32 is made self-releasing in any desired manner, here indicated as being provided with a flattened pivot pin 35 to be journaled in a slotted bearing not shown. Each articulation of the tubing 14 is provided with an overpressure valve and each end of the line charge 20 has secured thereto a drogue 36, the function of which elements will be described in connection with FIG. 3.

The launching of the above described weapon from a submerged submarine 27 will now be described in connection with FIG. 1 which illustrates from right to left successive stages in a launching. In the first stage, the

container 10 has become buoyant and is leaving its cradle 37 on the deck of the submarine 27. In the second stage, further inflation of the bladder 19 has started to eject the packaged line charge 20 which has forced off the removable bulkhead 12. In the third stage, the packaged line charge 20 has been completely ejected and the buoyant container ill, in separating therefrom, has disengaged the bell crank 32 after its being rotated to initiate inflation of the tubing 14. In the fourth stage illustrated, the container It continues to rise but the bladder 19 within it is about to rupture because of the reduced hydrostatic pressure, the tubing 14 is being inflated and has started toward assuming a linear configuration and the packaging strips 16 have been released. In the fifth stage illustrated, the bladder 1Q in the container has ruptured and the container 10 is falling towards the bottom while the line charge 20 continues to rise and become more linear. In the sixth stage illustrated, the container 10 has settled to the bottom and the line charge 20 has reached the surface and is substantially linear. In the final stage illustrated, the prow of an attacking surface vessel 38' has engaged the surfaced line charge 20 and has caused the line charge 20 to fold around the stem of the vessel 38 and in engagement with the sides thereof. As the vessel 38 drags the line charge 20 along with it, the drogues 36 unfold and eventually, as will be described in connection with FIG. 3, bring about explosion of the charge contained in the tubing 14.

As shown in detail in FIG. 3, each end of the line charge 20 is equipped with a booster charge 40 in physical contact with the first segment of high explosive 41 in the line charge 20; each segment of the high explosive 41 is housed in a nonexpansible canvas bag 42 for ease in handling. To further insure explosion of the charge 41, a short length of detonating fuse 43 is placed in contact with the adjoining faces of the booster charge 40 and the high explosive 41 and also between adjoining segments of the high explosive to constitute them a single charge. The distal end of the booster charge 40 is provided with a well 44 into which an electric blasting cap 45 having terminals 51 is adapted to be seated by a compressed spring 46 when a rod 47 carrying the delay cap 45 is released. As here shown, a detent 48 is held in restraining relation with the rod 47 against the bias provided by a compressed spring 49 by a pin 50, the removal of which pin allows the spring 49 to remove the detent 48 from the rod 47' and thus permit the spring 46 to seat the delay cap 45 in the well 44. At the time of its seating the terminals 51 of the delay cap 45 make contact with the output electrodes 52 of a power source 53 to initiate, after the delay period of the cap 45, explosion of the line charge 20. The drogue 36 is connected to the firing pin 50 through a lanyard 54 and a rod 55 which is yieldably restrained by a spring 56 in the direction to maintain slack in the lanyard 54. When the line charge 20 has been engaged by a ship and is dragged through the water at a speed greater than a predetermined minimum speed, the drogue 36 expands and exerts suflicient drag force on the rod 55 to overcome the resistance of the spring 56 and pull the firing pin 50 from the detent 48 thereby bringing about an explosion of the line charge 20 after the delay period of the blasting cap 45.

Inasmuch as in its intended use the line charge 20 will be launched from a considerable depth, the tube 14' when inflated at such considerable depth would have to be either unacceptably elastic or unduly robust in order to withstand the rapidly decreasing external pressure as the tube 14 rises toward the surface. Preferably, the inflated tube 14 is maintained at a substantially uniform volume by providing it with an overpressure valve for maintaining substantially constant the pressure differential between the inside of the tube 14 and the ambient pressure. The overpressure valve 30 shown in FIGS. 3 and 4 is a simple spring loaded poppet valve which as here shown includes a washer 60 having its outer rim sealed in the wall of the tube 14 and having its inner rim shaped to provide a seat for a valve 61. In accordance with an additional feature of the invention, the washer 60 forming the valve seat and the valve 61 are made of dissimilar metals such as copper and magnesium whose contacting surfaces react rapidly when immersed in sea Water so that after a time interval of an hour or two, depending somewhat upon the angle of the seat, the magnesium becomes sufificiently eroded for the valve to be pulled through the seat by the valve spring'62 thereby permitting the assembled line'charge 20 to sink. This self-sterilizing feature is not necessary to the functioning of the present invention per se, but is mentioned as an optional safety device which in the event the line charge 20 is not encountered by its intended victim, will shortly thereafter remove the mine from endangering subsequent ocean traflic.

The pincer 23 for severing the lanyard 23 as shown in FIG. 5 comprises a dog 28 pivoted in a sleeve 28' crimped on the lanyard 23 and adapted to be rotated to lanyard severing position by engagement of its depending tail with the wall 11.

Although the mines of the present invention may well be used for surface mining ahead of an enemy task force for damaging or slowing the progress of ships to render them more vulnerable to torpedo attack, they are provided primarily as one ansewer to the need frequently voiced by submarine oflicers for a last resort weapon for a submarine which can not evade a fix obtained by an attacking surface vessel. Submarine officers are understandably reluctant to permit anything to leave their vessel which may identify it as a submarine or fix its position. However, when it becomes certain that the enemy has a good fix on the submarine and all attempts to evade appear fruitless, any compromise of the submarines position by the use of the mine of the present invention will be of little additional detriment. With respect to the probable accuracy of placement of the surface mines of the invention, it should be pointed out that in a defensive situation critical enough to dictate its use by a submarine the probable accuracy of placement of the mines is closely related to the immediacy and accuracy of the attack against which the defense is directed.

The line charge 20 is made of sufiicient magnitude to puncture the hull plating of attacking type vessels and with the charge laying along the waterline of the vessel when it is detonated compartments usually separated by transverse bulkheads may be punctured and hence create a condition of lost longitudinal integrity which is difiicult to control with'the usual damage control measures. A charge containing two and one-half pounds of high explosive per linear foot will puncture inch hull plating when exploded in contact th'erewith.

While for the purpose of disclosing the invention a preferred embodiment thereof has been described in detail, it will be obvious to those skilled in the art that many modifications and variations thereof are possible in the light of the above teaching. It is therefore to be under stood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

In a Weapon of the character disclosed adapted for launching from a submerged submarine for defense against an attacking surface vessel, the combination of a cylindrical container open at its rear end and closed at its foiward end, a surface mine slideably received in the open end of said container, a removable bulkhead closing the open end of said container and adapted to be readily removed therefrom by rearward movement of said surface mine, a collapsed bladder disposed in said forward end, a source of gas under pressure connectable in fluid communication with said bladder for inflating said bladder for rendering said weapon buoyant in water and for expelling said surface mine from said container as said bladder expands from inflation, means for operatively connecting said bladder with said gas source, said surface mine comprising an articulated line charge encased in a flexible fluid tight tubular member having an expanded volume such that when said tubular member is filled with a gas said surface mine is buoyant in water and assumes a linear configuration, means actuated by the expelling movement of said surface mine from said container for filling said tubular member with gas, pressure sensing speed.

Referenees Cited in the file of this patent UNITED STATES PATENTS Ilfeld Oct. 26, 1948 10 102 49 6 Bisch Dec. 7, 1948 Defino Nov. 27, 1956 FOREIGN PATENTS Great Britain Oct. 7, 1927 OTHER REFERENCES Space Beacon, published in Astronautics, December 1958, vol. 3, No. 12, page 21 (copy Division 10, 

